NextLimit do provide free tutorials from their site that give an overview of Maxwell. Personally, I say stick with MR (Mental Ray). Its faster and can produce the same results, with a little more tweaking. MR is an industry standard and therefore if you are going forward to look at a career in 3D, then practice MR (esp in the VFX industry).

Alan, I believe one of Framestores main Renderers is MR?